Julia Roberts discusses George Clooney's engagement on Ellen Credit: Michael Rozman/ Warner Bros.

He's notoriously private, but George Clooney's longtime friend Julia Roberts is so excited about his engagement to human rights lawyer Amal Alamuddin, she couldn't help but spill!

Chatting on The Ellen DeGeneres Show Tuesday, May 6, the August Osage County actress, 46, admitted, "I think it is sublime."

Although she and Alamuddin have yet to meet in person, Roberts couldn't help gushing to Ellen DeGeneres about the trilingual, 36-year-old British attorney.

"She is beautiful and smart, and he is happy and that’s what matters to me," she beamed.

Clooney, 53, who co-starred with Roberts in the movie Ocean's 11, has described Roberts as "an amazing mother, an amazing wife and a great, great friend."